ArrayAdapter的使用

用到选项菜单和上下文菜单

public boolean onPrepareOptionsMenu(Menu menu)用来初始化选项菜单 

public boolean onCreateOptionsMenu(Menu menu) 用于创建菜单

public boolean onOptionsItemSelected(MenuItem item)用于选择时的处理

public void onCreateContextMenu(ContextMenu menu, View v, ContextMenu.ContextMenuInfo menuInfo)创建上下文菜单，需要在onCreate()时注册：registerForContextMenu

public boolean onContextItemSelected(MenuItem item)用于上下文菜单选择时的处理

package com.example.androidtest;

import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.util.AttributeSet;
import android.view.ContextMenu;
import android.view.KeyEvent;
import android.view.LayoutInflater;
import android.view.MenuItem;
import android.view.View;
import android.view.View.OnKeyListener;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.EditText;
import android.widget.LinearLayout;
import android.widget.ListView;
import android.widget.TextView;
import android.util.Log;

import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;

class ToDoItem
{
	public String getTask()
	{
		return task;
	}
	
	String task;
	
	public Date getCreated()
	{
		return created;
	}
	
	Date created;
	
	public ToDoItem(String _task)
	{
		this(_task, new Date(java.lang.System.currentTimeMillis()));
	}
	
	public ToDoItem(String _task, Date _created)
	{
		task = _task;
		created = _created;
	}
	
	public String toString()
	{
		SimpleDateFormat sdf = new SimpleDateFormat("dd/MM/yy");
		return "(" + sdf.format(created) + ")" + task;
	}
}

class ToDoItemAdapter extends ArrayAdapter
{
	int resource;
	
	public ToDoItemAdapter(Context _context, int _resource, List _items)
	{
		super(_context, _resource, _items);
		resource = _resource;
	}
	
	public View getView(int position, View convertView, ViewGroup parent)
	{
		LinearLayout todoView;
		
		ToDoItem item = getItem(position);
		
		String taskString = item.getTask();
		Date createDate = item.getCreated();
		SimpleDateFormat sdf = new SimpleDateFormat("dd/MM/yy");
		String dateString = sdf.format(createDate);
		
		if (convertView == null) {
			todoView = new LinearLayout(getContext());
			String inflater = Context.LAYOUT_INFLATER_SERVICE;
			LayoutInflater vi = (LayoutInflater)getContext().getSystemService(inflater);
			vi.inflate(resource, todoView, true);
		} else {
			todoView = (LinearLayout)convertView;
		}
		
		TextView dateView = (TextView)todoView.findViewById(R.id.rowDate);
		TextView taskView = (TextView)todoView.findViewById(R.id.row);
		dateView.setText(dateString);
		dateView.setText(taskString);
		
		return todoView;
	}
}

class ToDoListItemView extends TextView
{
	private Paint marginPaint;
	private Paint linePaint;
	private int paperColor;
	private float margin;
	
	public ToDoListItemView(Context context, AttributeSet attrs, int defStyle)
	{
		super(context, attrs, defStyle);
		init();
	}
	
	public ToDoListItemView(Context context, AttributeSet attrs)
	{
		super(context, attrs);
		init();
	}
	
	private void init()
	{
		marginPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
		marginPaint.setColor(Color.RED);
		linePaint = new Paint(Paint.ANTI_ALIAS_FLAG);
		linePaint.setColor(Color.BLACK);
		paperColor = Color.BLUE;
		margin = Color.CYAN;
	}
	
	public void onDraw(Canvas canvas)
	{
		canvas.drawColor(paperColor);
		canvas.drawLine(0, 0, getMeasuredHeight(), 0, linePaint);
		canvas.drawLine(0, getMeasuredHeight(), getMeasuredWidth(), getMeasuredHeight(), linePaint);
		canvas.drawLine(margin, 0, margin, getMeasuredHeight(), marginPaint);
		canvas.save();
		canvas.translate(margin, 0);
		super.onDraw(canvas);
		
		canvas.restore();
	}
}

public class MainActivity extends Activity {

	private ArrayList todoItems;
	private ListView myListView;
	private EditText myEditText;
	private ToDoItemAdapter aa;
	
	private boolean addingNew = false;
	static final private int ADD_NEW_TODO = Menu.FIRST;
	static final private int REMOVE_TODO = Menu.FIRST + 1;
	
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		
		myListView = (ListView)findViewById(R.id.myListView);
		myEditText = (EditText)findViewById(R.id.myEditText);
		todoItems = new ArrayList();
		aa = new ToDoItemAdapter(getApplicationContext(), R.layout.row, todoItems);
		
		myListView.setAdapter(aa);
		myEditText.setOnKeyListener(new OnKeyListener() {
			public boolean onKey(View v, int keyCode, KeyEvent event)
			{
				if (event.getAction() == KeyEvent.ACTION_DOWN) {
					if (keyCode == KeyEvent.KEYCODE_ENTER) {
						ToDoItem newItem = new ToDoItem(myEditText.getText().toString());
						todoItems.add(0, newItem);
						myEditText.setText("");
						aa.notifyDataSetChanged();
						cancelAdd();
						return true;
					}
				}
				
				return false;
			}
		});
		
		registerForContextMenu(myListView);
	}
	
	private void cancelAdd()
	{
		addingNew = false;
		myEditText.setVisibility(View.GONE);
	}

	@Override
	public boolean onCreateOptionsMenu(Menu menu) {
		// Inflate the menu; this adds items to the action bar if it is present.
		//getMenuInflater().inflate(R.menu.main, menu);
		super.onCreateOptionsMenu(menu);
		MenuItem itemAdd = menu.add(0, ADD_NEW_TODO, Menu.NONE, "New");
		MenuItem itemRem = menu.add(0, REMOVE_TODO, Menu.NONE, "Remove");
		itemAdd.setIcon(R.drawable.ic_launcher);
		itemRem.setIcon(R.drawable.ic_launcher);
		itemAdd.setShortcut('0', 'a');
		itemRem.setShortcut('1', 'r');
		return true;
	}
	
	public void onCreateContextMenu(ContextMenu menu, View v, ContextMenu.ContextMenuInfo menuInfo)
	{
		super.onCreateContextMenu(menu, v, menuInfo);
		menu.setHeaderTitle("Selected To Do Item");
		menu.add(0, REMOVE_TODO, Menu.NONE, "Remove");
	}
	
	public boolean onPrepareOptionsMenu(Menu menu)
	{
		super.onPrepareOptionsMenu(menu);
		
		int idx = myListView.getSelectedItemPosition();
		String removeTitle = "Title";
		MenuItem removeItem = menu.findItem(REMOVE_TODO);
		removeItem.setTitle(removeTitle);
		removeItem.setVisible(addingNew || idx > -1);
		
		return true;
				
	}
	
	public boolean onOptionsItemSelected(MenuItem item)
	{
		super.onOptionsItemSelected(item);
		int index = myListView.getSelectedItemPosition();
		switch (item.getItemId()) {
		case REMOVE_TODO:
			if (addingNew) {
				cancelAdd();
			} else {
				removeItem(index);
			}
			
			return true;
		case ADD_NEW_TODO:
			addNewItem();
			return true;
		}
		
		return false;
	}

	public boolean onContextItemSelected(MenuItem item)
	{
		super.onContextItemSelected(item);
		switch(item.getItemId()) {
		case REMOVE_TODO:
			AdapterView.AdapterContextMenuInfo menuInfo = (AdapterView.AdapterContextMenuInfo)item.getMenuInfo();
			int index = menuInfo.position;
			removeItem(index);
			return true;
		}
		
		return false;
	}
	
	private void addNewItem()
	{
		addingNew = true;
		myEditText.setVisibility(View.VISIBLE);
		myEditText.requestFocus();
	}
	
	private void removeItem(int _index)
	{
		todoItems.remove(_index);
		aa.notifyDataSetChanged();
	}
}

主界面的xml:

ArrayAdapter用到的xml: